I. Field of the Invention
This invention relates to pipeline pigs for use in filling or emptying pipelines, for efficient cleaning of the interior of pipelines, for internal corrosion control and for fluid separation and gathering. Particularly the invention relates to a type of squeegee cup for use as a part of a pipeline pig.
II. Description of the Prior Art
The use of apparatus that is moved by fluid flow in the interior of a pipeline is well known and is frequently referred to as a "pipeline pig". The terms "pipeline pig" or simply "pig" are commonly employed in industry. Pigs are employed during the construction of pipelines as well as during the operational life of pipelines. Some operators run pigs through their pipelines on a scheduled basis.
Pipeline pigs are essential for effectively filling or emptying a pipeline, for efficient cleaning of the interior wall of a pipeline, for internal corrosion control, for fluid separation and for gathering out fluids from within pipelines.
For general information as to the application and use of pipeline pigs, reference may be had to an article entitled "Fundamentals of Pipeline Pigging", authored by Burt VerNooy, appearing in Pipeline Industry, September/October 1980, published by the Gulf Publishing Company of Houston, Tex. For additional background information relating to pipeline pigs of the type to which the present invention pertains, reference may be had to the following prior issued United States Patents:
______________________________________ U.S. Pat. No. INVENTOR TITLE ______________________________________ 2,275,190 Lowry Water Main Cleaning Device 2,276,109 Smith Pipe-Line Cleaner 3,006,415 Burns et al Cementing Apparatus 3,496,588 VerNooy Pipeline Pig 3,576,043 Zongker Pipeline Pig With Spring- Mounted Scrapers 3,605,896 Perkins Liner Top Squeeze Plug Below Retrievable Tool 3,691,584 Landers Disc Supported Cup 3,857,132 Knapp et al Pipeline Pig Operable In Two Directions 4,069,535 Cato Pipeline Pig 4,083,074 Curtis Multipurpose Pipeline Pig 4,248,299 Roeder Packer Nose Assembly 4,275,475 Schwartz et al Pipeline Pig 4,378,838 Odgen et al Pipe Wipers and Cups Therefor 4,413,370 Payne et al Unitary Pig For Use In A Pipeline 4,893,684 Alexander Method of Changing Well Fluid 4,984,322 Cho et al Elastomeric Disc For Use On A Pipeline Pig 5,113,940 Glaser Well Apparatuses and Anti- Rotation Device For Well Apparatuses 5,127,125 Skibowski Pipeline Scraper 5,246,069 Glaser et al Self-Aligning Well Apparatuses and Anti-Rotation Device For Well Apparatuses 5,295,279 Cooper Cup For Use On A Pipeline 5,433,270 LaFleur Cementing Plug 5,533,570 Streich et al Apparatus For Downhole Injection and Mixing of Fluids Into A Cement Slurry 5,699,577 Rankin Magnetic Cleaning Pig ______________________________________